The oral, third-generation, irreversible epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI) osimertinib is superior to standard EGFR-TKIs including gefitinib and erlotinib as a first-line treatment for EGFR mutation-positive advanced non-small cell lung cancer (NSCLC), according to a recent study.
In a double-blind, phase 3 trial, researchers evaluated 556 patients with previously-untreated, EGFR mutation-positive advanced NSCLC. Patients were randomly assigned 1:1 to receive once-daily osimertinib (80 mg), or either once-daily gefitinib (250 mg) or once-daily erlotinib (150 mg).
The primary endpoint was defined as progression-free survival as determined by investigators.
Results of the study demonstrated that median progression-free survival was significantly longer with osimertinib (18.9 months) vs standard EGFR-TKIs (10.2 months), with a hazard ratio of 0.46 for disease progression or death. The researchers observed similar objective response rates in both those on osimertinib (80%) and those on standard EGFR-TKIs (76%). Additionally, median duration of response was 17.2 months in the osimertinib group compared with 8.5 months in the standard EGFR-TKI group.
The 18-month survival rate was 83% in patients on osimertinib vs 71% in patients on standard EGFR-TKIs, with a hazard ratio of 0.63 for death. Adverse events of grade 3 or higher occurred less frequently with osimertinib (34%) vs standard EGFR-TKIs (45%).
The researchers noted that data on overall survival had been immature (25% maturity) at the interim analysis.
“Osimertinib showed efficacy superior to that of standard EGFR-TKIs in the first-line treatment of EGFR mutation-positive advanced NSCLC, with a similar safety profile and lower rates of serious adverse events,” the researchers concluded. —Christina Vogt